You are climbing a stair case. It takes n steps to reach to the top.
Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?
很明显看出这是个斐波那契数列，但是我们一般不用递归的方法，而采用循环来求解
class Solution {
public:
int climbStairs(int n) {
if (n < 1)return 0;
vector<int> vec(n+1, 0);
vec[0] = 1;vec[1] = 1;
for (int i = 2;i <= n;++i)
{
vec[i] = vec[i - 1] + vec[i - 2];
}
return vec[n];
}
};
原文：http://www.cnblogs.com/csudanli/p/5877303.html